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How a rainbow works. Light passes across a boundary from air into water. As light crosses that boundary, the rays bend at different angles
The same thing that happens in a rainbow: white sunlight enters a raindrop and is broken into different colors heading in slightly different directions. The light is then reflected off the back of the raindrop and passes back into the air again,.

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Daniel L.

12/11/2017 03:37:40 pm

Refraction is everywhere in our lives. It's used in fiber optic cables, where there is total internal reflection and the light stays inside a cable, as a mean to send information in the form of light, at the speed of light. Refraction also causes rainbows, the different wavelengths that make up white light move at slightly different speeds, causing them to refract at slightly different angles, separating the light wave into a beautiful rainbow. Many magic tricks also take advantage of refraction, at certain angles, the light refracts and may not reach our eyes, causing something to disappear.

On the 3rd of December in 2017, a halo appeared around the sun in Sweden. This illusion was created due to the refraction of light. This rare occurrence happens when light travels through a high band of cirrus clouds more than 20 000 feet above the ground. These cirrus clouds are made of many ice crystals. (Water drops froze in air.) The light from the sunlight travels through the ice crystals, refracts towards the normal, and then travels back out at a different angle. Creating an illusion of a giant ring around the sun that looks like a sun halo.

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Ellen.T

12/14/2017 06:39:34 pm

A common way refraction is seen in our daily lives is through a magicians magic tricks. The magic trick where our eye perceives that the top half of a stick is not attached to the bottom half of the stick when half submerged in water is because of refraction. Because the light is travelling through different substances with different density's, the light rays will move and make it seem as if the object is not actually one full object. This is just one way that we can see refraction being used in our daily lives.

a magnifying glass refracts light because it has to bend light to different angles to be able to focus to a point.

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Aaryan P.

12/16/2017 07:34:13 am

Refraction is when light enters a new medium, and depending on the index of refraction it will go towards or move away from the normal (speed up/slow down). An example of refraction being something one should consider in the real world is with lifeguards. When someone is drowning in water, the light reflecting off their underwater bodies refracts when it reaches air. It speeds up and moves away from the normal, however, our brains extrapolate light backwards as if it came in a straight line. This means the lifeguard would think the person is deeper than they actually are, which they would need to take into account if they want to save someone in time. Another example is spear fishing. Using the same logic as the previous example the person trying to catch the fish would need to aim slightly higher than they think because the image of the fish refracts when it leaves water and reaches air. This would make the image seem lower as our brains can't extrapolate refraction, only light going straight

When someone stands in a pool with the water up to their waist, the persons legs seem to appear shorter than they actually are. This is because of refraction, when light changes speed as it enters a different medium (water to air), causing apparent depth. The light rays from the person's legs will go from more dense (water) to less dense (air) medium and bend away from the normal. The person viewing will still process the light as if it came in a straight line, and extrapolates the light rays back, therefore causing the legs to look shorter/higher up in the water than it actually is.

The law of refraction, which relates the degree of bending light to the properties of a refractive material, was discovered by a Dutch mathematician named Willebrord Snel van Royen in the early 1600's. Snel realized that there was a fixed ratio in refraction. The formula that he came up with, and is now popularly used, is named Snell's Law. The fact that his name in Latin was "Snellius", was why it was named "Snell's Law" and not "Snel's law".

An example of refraction would be binoculars. As we know, when an object is far away (beyond focal point) and it's light rays pass through a concave mirror, the image appears upside down. Binoculars solve this problem using refraction. Sets of prisms inside the binoculars refract light in such a way that the image is flipped and appears to be upright.

Source:
http://www.explainthatstuff.com/binoculars.html

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Andy M.

12/16/2017 05:50:05 pm

The law of refraction was first discovered in 1621 by Willebrord Snell who was a Dutch astronomer and mathematician. He states that the ratio between the index of refraction of the first and second medium is equal to the ratio between the sin of the first angle and the sin of the second angle which can be represented by n1 n2 = sin a1 / sin a2. This law went unpublished until it was mentioned by another Dutch mathematician named Christiaan Huygens in his treatise on light. Which was a book he wrote in 1690 about his wave theory of light.

An example in our everyday lives of refraction is directly in the glasses we drink from. The shapes of these glasses also cause the differences in the image produced. For example in the image below, a wine glass is shown. At the top the wine glass curves in causing for an upright image in the glass. When the right curves outward, the image becomes inverted and when it curves inward at the bottom it becomes upright again. The shapes and the type of glass cause differences in the image with the use of refraction.

Refraction occurs when light travels between two different media. An example of when I have seen this is at an aquarium in Quebec. When the polar bears swim in the water, they sometimes keep their heads above while the rest of their body is underwater. In that situation, the two media the light is travelling between is air and water - the rays come closer to the normal when they are in water making the head of the polar bear look not directly connected to the rest of the body.

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Tina.N

12/16/2017 08:34:09 pm

An example of refraction is a rainbow, which is shown by another way of refraction called dispersion. Dispersion is refraction using white light and can separate into different colours. Different colours appear because they have different speeds. That is why red is on top (use less energy) and purple is on the bottom (has the most energy)
References: ms.loree's notes

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